Sewing-machine motor



Sept. 20, 1927. 1,643,191

A. F. WELCH 'sswme MACHINETMOTOR Filed March 18, 1924 inventor: Alfred E Welsh,

His Attorney.

provide an electrically driven sewing ma- Patented Sept. 20,1927. it 1 I v a 1,643,191

UNITED STATES PATENT oFFIcE.

. m r. WELCE, or roar warns, INDIANA, ,assrsrron 'ro GENERAL ELECTRIC corrrnmr, n oonronarronor rrnw'yon z.

snwme-rmcnmn moron.

Application filed March '18, 1924'. Serial 1%. 700,158.

My invention relates to an electric motor Im' the accompanying drawing, Fig. 1, is 60 d i for wing machin s an elevation of a sewing machine head part- Sewing machines of the motordriven type 1y in= section showing a motor built in acnow on the market are usually provided with cordanoe with my invention, and Figs. 2 and I motors which are removably mounted upon ,3 are. views of l the machines. The motors on such machines Fig- 1 0f the drawing, a sewing maoccupy considerable space and are' chlne is shown having an arm 10 which supless in the way. In order that the motor P dle ar head 11 as is the usual shall occupy the minimum spaee. it h h r practice. The other end of the arm 10 is 10 tqfore been'proposed to l t th t --1 provided with a flared 0r enlarged portionh a iti th t {t can be "di e ti 12 wh1ch forms the frame. of an electric -nee-ted to the sewing machine shaft, Thi motor. A field structure 13 of an electric is best done by locating the mot t th motor 1s secured in the frame thus formed end of the machine head and utilizing the and Q I field winding 14. A shaft 15 rotating parts of the motor as the flywh l for dIlVlIlg the sewing machine elements exl t jf th hi tends through the arm 10 and supports an AS heretofore constructed order to pro. armaturemember is adapted to IO- vide an exposed rotating part similar t tats-within the field structure 13 and carry the ordinary flywheel which can be used by all re Win ing 17. The armature 9 th Operator as t ti a d topping member 16 "is mounted upon a spider 19 means, the armature of-the motor has been W r e a Shield member 18. The

arranged to rotate outside of the stationary Shield m s Secured Spider field which is secured to the machine head. h the sh ft 15 and extends outwardly and 1 Such a construction is difiicult to manufac Q the fl r d portion 12 toiorm a protecture and is not as desirable as a motor built 151% v rlng for the motor and also provide in accordance with standard practice, that means wh re y the motor can be controlled is, with the armature rotating within a stay hand by the operator, as when starting tionary field structure, 3 and stopping the machine.

It is one of the obiectsof my invention to I T e splder 19 carries a commutator 20,

' and 'ad aCent to the commutator and mountchine in which the motor is built within the ed .w thin' the flared portion 12 of the a head of the machine and forms a part there-' 1 re bPUShBsQLWhich co-opera e With he of. and which at the same time avoids the comm r 1 to commutate the armature aforementioned objectionable features. Wmdmg 7 When the hlOtOr .iS perating.

35 A further object of my invention isto pro- Th br shes 21'are supported by brushholdvide an electric n t0r having means whigh ers 22 are biased toward the commutator will permit the operator to start and stop 20 by springs 23. The brushholders 22 are the machine by hand in much the 'same manlocated 1n recesses 24 in the arm 10 and are Q nor as iscustomary at present among opernsulated therefrom by insulation 25. The r 0 ators usingthe usual type of domestic afield structure 13 of the electric motor is hi a suppdrted within the flared end 12 of the With the above and other objects in view, arm 10 and is composed of magnetic matewhich will appear asthe description pro-- r al having conductor slots in its inner peceeds, my inventionresides in a novel conp y in Which the field winding 14 is struction, combination and arrangement of moun ed. The armature member 16 of the arts more fully described hereinafter and electric motor is composed of similar magparticularly defined in the claims appended netic material having conductorslots in its hereto and forming a part of this specificaouter periphery into which the armature tion. winding 17 is mounted. The armature memher 16 is mounted in the outer periphery of the spider 19 which can-be made ofany suitable -material such as bakelite or the like. Spider 19 is provided with a hub lining 26 of suitable bearing material such as brass or bronze and it is adapted to rotate freely aboutv the end of the shaft 15 when disengaged therefrom by a clutch which will be described in more detail hereinafter.

A rotatable member built of a relatively light spider and a relatively heavy armature structure as described above will pos sess'considerable flywheel effect due to the fact that the weight of the armature member 16 and commutator are removed from the center of rotation. It is therefore possible todispense with the usual flywheel and it also makes it unnecessary to rely upon the protecting shield 18 for any substantial flywheel effect. The commutator '20 is mounted on the side of the spider 19 and is adapted to commutate the winding 17 on the armature member 16 of the electric motor when it is in operation. Spider 19 is provided with passageways 27'which tend to set up a circulation of ,air within the enclosure about the windings 14 and 17.

formed by the flared end 12 and the shield member 18. The shield member 18 is provided with openings 28 through which fresh air enters theenclosur-e and the flared end 12 is provided with openings 29 through' which some of the circulating air is.discharged, the. remaining portion of dIS- charged air' passing between the outer edge of the shield member'18 and the outer side of the flared portion 12015 the arm 10. The

' hand of the operator in starting and stopping the machine.

In order to permit bobbins to be wound by the motor without driving the machine I provide a clutch for disconnecting the sewing machine shaft 15 from the rotatable member of the motor. This clutch consists. of a friction washer 30 keyed to the shaft 15 by tongues '31 which engage keyways in the end of the shaft 15, and a nut 32 which is threaded in the end of the shaft15l When the thumb nut 32 is tightened the rotatable member will be clampedto the shaft 15 between the friction washer 30 and a shoulder 33 formed on the shaft 15. The friction washer 30 as shown in Fig. 2 is provided with an outwardly extknding tongue 34 which cooperates with a screw 35 in the thumb nut 32 to prevent the latter from running off the'shaft 15.

- Referring to Fig. 3, the brush leads are shown having a cli 36 which engages the groove 37 in the rushholders 22 and is adapted to carry thecurrent to the brushes 21. This method of connecting the brushes permits the brushholders to be removed and the brushes replaced with a minimum of inconvenience.

Although I have described my invention with considerable detail and with respect to certain particular forms, I do not desire to be limited to such details since many changes and modifications may well be made without departing from the spirit and scope of my invent-ion. I

What I claim as new and desire tosecure by Letters Patent of the United States is:

1. In a sewing machine. the combination of an arm having a needle bar at one end and flared at its other end to form the frame of an electric motor, a field structure for said motor supported within said flared end, a shaft for driving said machine extending into said arm, an armature member mounted upon said shaft and rotating within said field structure, and a shield member secured to and rotatable with said armature member extending over and about said field structure and adapted to be used as a hand operated means.

2. In a sewing machine, the combination of an arm, a field structure supported .by said arm, a shaft for driving said machine extending into sald arm, an armature member mounted upon said shaft and rotatable within said field structure, and a hand operating means secured to said armature member and constructed to extend over and enclose said field structure.

3. In a sewing machine, the combination of an arm, a field structure supported by said arm, a shaft for driving said machine extending into saidarm, an armature member mounted upon said shaft and-rotatable of an arm having a needle bar head atv one end and flared at its other end, a field structure of an, electric motor supported by said flared end, a shaft extending into said arm, an armature member of an electric motor rotatably mounted upon said shaft, a shield member forming a hand wheel secured to said armature member and arranged to meanscfor securing said armature member to said shaft.

extend over the field structure, and friction i withinsaid field structure, a hand operating 5. In a sewing machine, the combinsition of an arm, a field structure supported by said arm, a shaft extending into said arm,

' a spider of relatively light mass secured to said shaft, a narn1ature structure of relatively large mass secured to the rim of said spider, and a cue shaped shield'member secured to said spider extending over and about said field structure, said armature structure and spider forming an internally 10 rotating flywheel and said shield forming an external hand operating means. I

"In witness whereof, I have hereuntoset' my hand this 15th day of March, 1924.

ALFRED F. WELCH. 

